noun, noun which may take the genitive case particle 'no'
double; twice as much
Used as a noun or の-modifier for 'twice the amount, size, time, etc.' Common in patterns like 倍になる, 倍にする, and 倍の.
修理には予想の倍の時間がかかった。
The repair took twice as long as expected.
売り上げを来年までに倍にしたい。
We want to double sales by next year.
counter
times as much; -fold
Counter-like suffix attached to numbers to express a multiplier, as in 3倍 'three times' or 10倍 'tenfold'.
この薬は水で十倍に薄めて使います。
This medicine is used after diluting it tenfold with water.
今年の応募者数は去年の三倍です。
The number of applicants this year is three times last year's.
counter
one in n; n to one odds
In competition ratios, selection odds, and similar contexts, N倍 can mean that there are N people or chances for one place: effectively 'one in N' or 'N to 1'.
入試の競争率は四十倍だった。
The entrance exam had a competition ratio of forty to one.
この講座の抽選倍率は二十倍を超えた。
The lottery odds for this course exceeded twenty to one.
A noun meaning magnification, multiplier, or competition ratio; 倍 itself is the multiplier word or suffix used in expressions like 3倍.
A specific fixed multiplier meaning 'double' or 'twice'; 倍 can stand alone for 'double' or attach to many numbers.
Means 'half' rather than 'double' or '-fold', and is often the practical opposite idea of 倍.
A Sino-Japanese word read ばい, written with 倍; the spelling is conventionally associated with doubling and multiplication.